Page 265 - Understanding Psychology

the subject (the depressed woman and the wandering dog in our exam- ples) operates on or causes some change in the environment. This pro- duces a result that influences whether the subject will operate or respond in the same way in the future. Depending on the effect of the operant behaviors, the learner will repeat or eliminate these behaviors to get rewards or avoid punishment.
How does operant conditioning differ from classical conditioning? One difference lies in how the experimenter conducts the experiment. In classical conditioning, the experimenter presents the CS and UCS independent of the participant’s behavior. The UCR is elicited. Reactions to the CS are then observed. In operant conditioning, the participant must engage in a behavior in order for the programmed outcome to occur. In other words, operant conditioning is the study of how voluntary behavior is affected by its consequences (see Figure 9.5).
REINFORCEMENT
Burrhus Frederic (B.F.) Skinner has been the psychologist most closely associated with operant conditioning. He believed that most behavior is influenced by a person’s history of rewards and punishments. Skinner trained (or shaped) rats to respond to lights and sounds in a spe- cial enclosure called a Skinner box (see Figure 9.6). To conduct this experiment, a rat is placed inside the box. The rat must learn how to solve the problem of how to get food to appear in the cup. (This can be done by pressing a bar on the cage wall.) The rat first explores the box. When the rat moves toward the bar, the experimenter drops food into the cup. The food is important to the hungry rat. After the rat begins to approach the cup for food consistently, the experimenter begins to drop food into the cup only if the rat presses the bar. Eventually, when the rat is hungry it will press the bar to get food.
The food that appears in the cup is a rein- forcer in this experiment. Reinforcement can be defined as a stimulus or event that increases the likelihood that behavior will be repeated. Whether or not a particular stimulus is a rein- forcement depends on the effect the stimulus has on the learner. Examples of reinforcers that people usually respond to are social approval, money, and extra privileges.
Suppose you want to teach a dog to shake hands. One way would be to give the animal a treat every time it lifts its paw up to you. The treat is called a positive reinforcer. In this example, the dog will eventually learn to shake hands to get a reward.
Your dog will stop shaking hands when you forget to reward it for the trick. Extinction will occur because the reinforcement is withheld, but
Reading Check
How is operant condi- tioning different from classical conditioning?
reinforcement: stimulus or event that follows a response and increases the likelihood that the response will be repeated
Figure 9.5 Operant Conditioning
Behavior
Positive Negative reinforcer reinforcer
Changed behavior
We do not just react to our environment, we behave in ways that seem designed to produce certain environmental changes. For example, I flip the light switch to illuminate a room. I say, “Please, pass the salt,” to get the salt shaker. According to the diagram, what must hap- pen for behavior to change?
Chapter 9 / Learning: Principles and Applications 251